Aspirating smoke detectors are known and useful in a variety of commercial and industrial environments. When commissioned, an aspirating smoke detector establishes an airflow baseline for the air that flows through the detector. During the operating life of the detector, current airflow is monitored and compared to the baseline that was established during commissioning. When a current airflow measurement deviates from the baseline that was established during the commissioning, a trouble condition is reported to the operator of the detector.
Aspirating smoke detectors are often used to monitor the current airflow on the return air grills for HVAC units. During operation, HVAC units may continuously cycle on and off, which can result in periods of high airflow followed by periods of stagnant air. These changes in airflow can cause the aspirating smoke detector to generate the trouble condition due to the current airflow when compared to the baseline that was established during the commissioning.